許溝大橋位于洛三高速公路k49+453.37~k49+946.51,三門峽義馬(ma)市(shi)近郊,該橋橋孔布置自(zi)東(dong)向西:9×20m+220m+4×20m,全長493.14m。由中(zhong)鐵十一局(ju)集團第(di)一工(gong)程有(you)限(xian)公司施(shi)工(gong)建設(she)。
該橋橋孔布置(zhi)自東向西:9×20m+220m+4×20m,全長493.14m。主孔為(wei)等截面(mian)懸鏈線箱形無鉸拱(gong),截面(mian)為(wei)三室(shi)箱,拱(gong)軸系數m=1.543,凈跨徑L0=220m,凈矢高(gao)f0=40m,矢跨比f0/L0=1/5.5。拱(gong)上建筑為(wei)13-17.5m先張預應力混(hun)凝土空(kong)心(xin)板及(ji)雙(shuang)(shuang)柱(zhu)式排架立(li)柱(zhu),橋面(mian)連續(xu),柱(zhu)間(jian)設橫向聯系。東西引(yin)橋為(wei)20m預應力混(hun)凝土空(kong)心(xin)板梁(liang),橋面(mian)連續(xu),下部為(wei)雙(shuang)(shuang)柱(zhu)式墩臺(tai),基礎為(wei)鉆(zhan)孔灌注(zhu)嵌巖(yan)樁(zhuang)。
該橋橋寬為24m,分(fen)上(shang)(shang)(shang)、下行,單幅橋寬為12m(11+2×0.5m墻式護(hu)欄)。設(she)計荷載(zai)為:汽(qi)-超(chao)20,掛(gua)-120。主(zhu)拱(gong)拱(gong)座為重力(li)式基礎,置于樁基或完整砂(sha)巖上(shang)(shang)(shang)。上(shang)(shang)(shang)下行之間(jian)(jian)設(she)3cm沉(chen)降縫,每個(ge)拱(gong)座混(hun)凝土(tu)量6000m以上(shang)(shang)(shang),屬(shu)大體積混(hun)凝土(tu),采取基坑滿注,提高(gao)拱(gong)座背(bei)后(hou)土(tu)抗力(li);主(zhu)拱(gong)拱(gong)箱采用C50混(hun)凝土(tu)。上(shang)(shang)(shang)、下行拱(gong)圈之間(jian)(jian)為加強聯(lian)(lian)結,設(she)6處聯(lian)(lian)結系。
許溝(gou)大橋位于(yu)洛三高速(su)公(gong)路k49+453.37~k49+946.51,三門(men)峽義(yi)馬市近郊,常(chang)窯水庫下(xia)游,跨越許溝(gou),溝(gou)中常(chang)年(nian)無水。溝(gou)槽內地(di)勢較(jiao)為(wei)平坦,表層(ceng)為(wei)亞砂土,下(xia)層(ceng)為(wei)卵(luan)石層(ceng);兩岸地(di)質(zhi)較(jiao)好,表層(ceng)有(you)0~3m的(de)沖積亞砂土和卵(luan)石層(ceng),下(xia)層(ceng)為(wei)泥質(zhi)粉砂與粉砂質(zhi)泥頁巖互層(ceng)。該地(di)區最(zui)大風力為(wei)20m/s,有(you)霜期為(wei)180~240天。